Modern elevator installations or so-called fire service elevators, which are designed additionally for this purpose, have to ensure reliable operation even in the case of fire, on the one hand for evacuation of persons and/or material, which is at risk, from the floors affected by the fire and on the other hand also for the transport of fire service personnel and their extinguishing material. In both cases the use of extinguishing water—whether by means of a sprinkler installation or by the fire service or both—should not have the consequence that the elevator installation or the fire service elevator no longer functions.
This means that the electrical components of the elevator installation must remain dry. Moreover, it has to be ensured that the supporting and driving means do not become so wet that an uncontrollable slip arises between the drive pulley and the supporting and driving means. Slip can arise particularly easily, because the extinguishing water on the one hand can directly have a disadvantageous influence on the coefficients of friction between the drive pulley and the supporting and driving means or can change the viscosity of any lubricant present and on the other hand usually contains soap for improved combating of fire.
The slip occurring between drive pulley and supporting and driving means thus leads to a reduction of traction or even to a complete loss of traction of the elevator installation and—in the case of a significant difference between the weight of the elevator car and the weight of the counterweight—possibly to an uncontrolled travel of the elevator car, which has to be stopped by the safety brake thereof. The faultless functioning of the safety brake or the braking retardation of the brake shoes thereof on the guide rail can, however, in turn be guaranteed only if the brake shoes or the guide rail are not moistened by (soapy) extinguishing water.
All these preconditions make it necessary for the extinguishing water to be drained or collected in controlled manner. The extinguishing water normally penetrates via the shaft doors of the elevator shaft into the latter. International published specification WO 98/22381 A1 discloses an elevator installation with closed drainage system at the shaft doors as well as mechanically positively interengaging flow barriers at the sliding doors of each shaft door. In this way it is sought to keep the elevator shaft free from extinguishing water over its entire height at the outset by means of a closed outflow system. However, it is disadvantageous with this solution that each floor has to be equipped beforehand at high cost with appropriate drain pipes and the said flow barriers.